The keeping of reptiles and amphibians in captivity is a rewarding and fulfilling hobby for thousands of people, and indeed a profession for many. Unfortunately, from time to time issues arise regarding the keeping of animals that due to any number of reasons may not be suited as a “pet” animal. These reasons vary from complicated husbandry requirements to the large adult sizes potentially attained by some species. For these reasons it is the recommendation of the Herpetological Society of Ireland that anyone thinking of acquiring a reptile or amphibian as a pet conducts thorough research into all aspects relating to the species they wish to keep, including captive care and potential adult sizes of both sexes.

This article aims to discuss the issue of the keeping of Turtle species with large growth potential. This discussion will include accurate information regarding these animals, their native ecology and advice for their captive husbandry, as well as the problems posed by the abundance of unwanted turtles and some options that are available to you if you have an animal you can no longer keep.

For the purposes of this article turtle species with the potential to become large enough to be unmanageable in an indoor environment include;

The Red-eared slider (Trachemys scripta elegans)

The Yellow-bellied slider (Trachemys scripta scripta)

The Cooter species (genus Pseudemys)

The Common Snapping turtle (Chelydra serpentina)

The Alligator Snapping turtle (Macrochelys temminckii)

American Softshell turtles (genus Apalone)

African and Asian Softshell turtles (genus Trionyx)

There are many more types of turtles that become too large to be easily kept in an indoor setting, but they rarely make their way into the pet trade and so have not been covered in this list. All of the turtles listed above are readily available in the pet trade, and unfortunately are often sold accompanied by incorrect husbandry advice and misleading estimates of true adult size. This has resulted in the deaths of a great number of animals either at a young age or before reaching adult size due to incorrect husbandry, as well as a surplus of adult animals that have outgrown their enclosures and are no longer wanted by their owners. It is sadly the case that some of these animals are subsequently abandoned in Irish waterways, ponds and lakes.

An alligator snapping turtle. Photo credit: Christopher Evans

Unfortunately a number of these species also have invasive potential as adults. This means that they could potentially survive the winter if released into the wild in Ireland. Whilst it may still be too cold for them to breed here, all of these species can reach 30 years of age and so may still pose problems for native ecosystems during the course of their lifetime.

It should be remembered however that despite the potential difficulties of keeping large turtles in an adequate living standard it is by no means impossible. It requires time, effort, space and more importantly a passion to keep your animal in the best condition that you are able. One hopes this article will also be interesting to the dedicated keepers that may read it, as it is intended to be a balanced overview concerning keeping large turtles in captivity.

Before delving into advice on the husbandry requirements of these turtles it will be useful to cover a little of their natural ecology and behaviours as this impacts on how they are kept in captivity.

Ecology of large turtle species –

Each of the groups of turtles mentioned above has a slightly different ecology in the wild. It can be useful to take this into account in many aspects of their captive husbandry, in order to keep them happy and healthy. For instance, species that are commonly observed basking in the wild will require a place where they can get fully out of the water and bask under a heat spot, whereas species that spend a lot of time concealed on a river bed will need deeper substrate, along with rocks and crevices to hide in underwater. These things can be taken into account when designing enclosures to make an enclosure that is naturalistic, interesting to look at and functionally beneficial to the turtle. Obviously there is far more information than can be covered in depth in this article and anyone wishing to research the ecology of their chosen species will find a wealth of information available to them in books and on the internet.

River cooter. Credit: Laurent Lebois

The Sliders and Cooters are groups that can be dealt with together, being very similar in ecological niche and habits. They are widespread species found in North, Central and South America. These are the turtles that will most often be seen basking on logs and river banks, and this is reflected in the fact that this group is occasionally known as the “Baskers”. These turtles can grow very large, with females reaching 12-14 inches maximum size for the slider species, and a slightly smaller 8-10 inches in the Cooter species. Both Cooters and Sliders are voracious predators, eating almost anything that they can catch. They are active hunters and foragers. Both of these facts should be taken into account when caring for these turtles in captivity, a variety of foods should be offered, and it does no harm at all to make the turtle actively look for its food. These types of turtle have a very fast growth rate, attaining adult size in 3-4 years.

Yellow bellied sliders. Photo credit: Rob Gandola

The Snapping Turtle species are quite different in ecology to the Slider and Cooters. They also occur in North, Central and South America, but occupy a different ecological niche. They achieve much more massive sizes, with Common snappers often reaching up to 20 inches carapace length and Alligator Snappers reaching up to 30 inches. They also have much more bulk, reaching weights of up to 30kg (Common snapper) and 70kg (Alligator snapper) for large captive individuals. They are rather slower growing than a slider or cooter, taking up to 12 years to reach maturity. Like the other turtles they will consume pretty much anything that they can fit in their mouths. However, they are very sedentary animals, relying on a sit-and-wait hunting strategy, lying concealed on the river bed with their mouth wide open, waiting to snap shut on any animal that wanders by. This fact has two implications for their captive husbandry, firstly, they can gain weight very easily as they do not move around foraging to get exercise. This is compounded by the fact that many keepers over feed them, whether accidentally as they do not realise how infrequently these turtles may catch prey in the wild, or deliberately to make them grow faster. Secondly, due to their hunting method the strength of the bite of these turtles is phenomenal, an in a large individual could potentially cause injury to a person.

There are numerous genera of “Softshell” turtle, and among them they boast some of the largest freshwater turtles in the world. They have a wide distribution, being found in the Americas, in Africa and in Asia. The very largest species do not find their way into the pet trade; however those that do are still capable of reaching very large adult sizes. Depending on species and sex they reach an adult size of 12-24 inches. The Softshell turtles are different in habits once again. Like the other two groups they are voracious feeders, consuming insects and other invertebrates when young, and mammals, birds and fish as they get larger.

Florida Softshell Turtle. Credit: Andrea Westmoreland.

These turtles bury themselves in the sediment of shallow water bodies, with only their heads showing, and prey on passing fauna. They have elongated necks and nostrils on the end of their snout to enable them to access the surface to breathe without moving from their hiding place. They will also actively hunt prey, especially when young.

All of these turtles may live 30 years or more in captivity, with the snappers having the longest reported life-spans.

Husbandry –

Due to the large differences between hatchling and adult sizes occurring in these turtles it is necessary to view their husbandry requirements in two parts.

Young individuals –

As young individuals all of the species listed above can be housed in any standard aquarium. They all require large water areas, but also the provision of a dry area where they can get fully out of the water in order to bask and let their shells dry out if they wish. This can either be an area of raised substrate or a floating turtle dock, of which there are many forms commercially available. All turtles should be provided with water deep enough to be able to swim in, however in one place the water should only be deep enough that at full stretch the turtle can reach the surface to breathe while keeping their hind feet on the substrate. This means that the turtle can rest while under water. Remember that in the species like snappers and softshells who habitually conceal themselves below the substrate it will be necessary to have at least part of the water at the correct depth that they can breathe (again at full stretch) without having to leave the bottom and come to the surface, the rest of the water can be deeper to allow swimming room.

To keep the water clean it would be advisable to use a filter and a pump, as poor water quality can cause health issues with your turtle. Turtles can make their water dirty very quickly indeed, and a properly maintained filter will help to reduce the frequency with which the water needs replacing. All species as juveniles will require a heater in the water, and the water temperature will vary between species.

All turtles should be provided with a basking spot; however there are multiple ways to go about this. Most commonly an incandescent or ceramic heating bulb suspended above the land area is used. In a small enclosure the basking spot may also be used to warm the water as well as the land instead of a heater, but this method is more imprecise. A UVB source is essential for healthy growth of bones and shell. It might be possible to use the UV bulb as the basking spot depending on the type of bulb used. Two points should be remembered here, the positioning of the basking bulb should be such that some portion of the dry area remains unheated, and any heating bulb should be used in conjunction with an appropriate thermostat.

Diet should vary where possible, many of the commercially available dried turtle foods are nutritionally complete, but all animals benefit from variety and a number of other foods can be offered from time to time, this depends on species of turtle but for young animals generally live insects make a good treat. This also allows the turtle to hunt as it would in the wild. A source of calcium such as cuttlebone should be offered from time to time, and insects can be gut-loaded with calcium before feeding. Once the turtle is large enough occasional whole vertebrate prey items (i.e. mice) will be a good source of organic calcium. One major problem with captive turtles is over feeding. This can have serious health implications for the turtle as well as making the enclosure very dirty very quickly. The appropriate frequency of feeding will vary between species and this is another thing that should be researched by a responsible keeper.

Adults –

As the turtle grows the size of the enclosure required will grow also. Until too large for an aquarium the husbandry advice above applies to turtles of any age. As adults some species may not require such high temperatures, and the frequency of feeding can also be reduced.

Unfortunately it is the case that for the species dealt with in this article the only suitable way to house an adult is in an outdoor enclosure, such as a pond. Some species can survive year round outdoors in Ireland (e.g. Sliders, Cooters, and Snappers). Other species or smaller individuals will not survive the winter cooling/hibernation and so will need to be brought into a house or shed in a temporary enclosure for the winter months. A basking spot and UV will need to be provided for the indoor period. The UV requirements of the turtles will be met by basking in daylight during the summer months. As with the indoor enclosures, outdoors turtle habitats require a pump and filter to maintain the water quality.

Keeping turtles in a pond is very different from keeping them indoors, and there are many different issues to consider. Again a dry land area will need to be provided for basking and drying of shell. Can turtles co-habit with fish? Well, generally fish are part of the natural diet of the sliders and cooters, and a Snapping turtle will make short work of your koi. If enough food is provided for the turtles then they may co-exist well enough, but fish will never be off the menu. It is also the case that some pond fish may carry parasites that can affect the health of the turtle. Care needs to be taken to ensure a correct diet is maintained, all these species will be able to find food in the pond environment, but that will not be enough to maintain their condition and so a feeding regime must still be observed. This can either be in pellet/specialised diet form or whole animal form depending on the species of turtle.

During winter smaller individuals will need to be brought inside. Larger individuals will need plenty of underwater places to bury/lodge themselves. It may also be necessary to give them a helping hand up in the spring, and an easy way out of the pond must be available as they may be too lethargic to climb out of a more steep-sided pond.

The most important tip for converting a pond??… MAKE IT ESCAPE PROOF. This could either be in the form of a walled garden or a 4ft fence surrounding the pond area. Bear in mind that turtles will climb low fencing and can also dig under it, so the bottom needs to be sunk in to the ground.

A well thought out and designed pond enclosure for turtles can look amazing in a garden, but design it to be robust as turtles will re-arrange anything movable to suit themselves, and they may well eat any pond plants put in.

African Softshell Turtle. Credit: Ruben Undheim

Softshell turtles are the least suitable for outdoor living, as they have more delicate requirements. A good solution for housing adults and other large specimens of these turtles is to purchase a specialist “tub”. Companies such as Waterland and ZooMed sell large plastic bath-tub sized enclosures designed for turtles/crocodilians. They have a large water area with a ramp up to a raised area to provide dry land. These can be kept in a shed or other building and all necessary lighting etc can be suspended above. This type of enclosure provides excellent housing for turtles of all sizes.

In Summary –

There are many aspects to consider when dealing with any pet animal, regardless of species. This article has been designed to give an overview of some of the problems regarding keeping turtle species where large adult sizes can be attained, and therefore there has not been scope here to delve too deeply into all the aspect of husbandry and captive care. Hopefully the brief overview given here will be enough to encourage readers to do more research into these animals for themselves.

It is true to day that certain species of turtle should not be viewed as ideal “pet” animals. That is not to say that they should not be kept by private keepers, but it has to be considered that many people wishing to own a turtle do not have the facilities to maintain an adult animal of these species.

A musk turtle. Photo credit: Laurent Lebois

Happily there are a number of turtle species readily available in captivity that do not reach the large adult sizes of the Sliders, Cooters, Snappers and Softshells. These smaller species are much better suited to captivity (i.e. will not outgrow an aquarium). They may be more expensive to buy initially than Sliders or Cooters, but they will cost less to keep in the long run as multiple housing upgrades will not be required. These smaller species include the Musk turtles (genus Sternotherus), the Map turtles (genus Graptemys), and Painted Wood turtles (Rhinoclemmys pulcherrima). Musk turtles reach a maximum female size of 5 inches, certain species of Map turtles are the largest on this list, where large adult females may still reach almost 10 inches. Other small species do come into the pet trade from time to time but are rarer for various reasons, from difficulty of captive breeding to stricter importation laws.

The most important thing to remember when considering turtles in the pet trade is to be a responsible buyer/keeper. If you want a turtle that can live in an aquarium for life then it is the responsible thing to do to buy a species that will stay small as an adult. This is possible once a little research is done beforehand. If you want a turtle that will grow large, or if you want to have a turtle you can keep outside then the responsible thing to do is to re-home one. To “re-home” a turtle is to take on one that has outgrown its owner/enclosure/could not be cared for any longer and is therefore unwanted. Currently there is a very real problem concerning large numbers of unwanted adult turtles in Ireland. These turtles were bought because they are cute when young and they are cheap. As these turtles begin to outgrow their enclosures they become unwanted and their owners are forced to find new homes for them. There are always turtles of various species needing good, permanent new homes if someone was willing to take one in.

Painted Wood Turtle. Photo credit: Cat Hendry

And on the flip side of the coin, what should you do if you have a turtle you can no longer care for? Unfortunately this can be a difficult situation. There are many turtles needing homes and not too many people that have the time/space to care for them. It is not really an option to hope to sell the turtle, as there are so many available for free to anyone seeking a large turtle. Zoos cannot take them in for bio-security reasons, as they cannot risk a disease being brought into their collections. Some people feel they can release the turtles into the wild, it cannot be stated strongly enough that RELEASING A TURTLE INTO THE WILD IS NEVER AN OPTION! The good news is that there are people who look for large turtles to keep, however it can be difficult to find a private keeper wishing to do so. There are specialist rescue organisations in Ireland who are able to take them, as well as private keepers who specialise in keeping these animals once they reach adult size. Searching the internet is a good way to find rescue/rehoming centres, such as the National Exotic Animal Sanctuary in Co. Meath.

So in conclusion, turtles can make excellent, entertaining and rewarding pets. However certain species are not suitable for everyone due to the large adult sizes they attain. Please be responsible when acquiring turtles and only buy species that will not outgrow the enclosures you can provide. Please also consider rehoming a turtle if at all possible before you buy one. Release of turtles or any other exotic animal into the wild is never an option; exotic species can cause massive problems for Irish native ecosystems and their flora and fauna. This is especially the case with Sliders, Cooters and Snapping turtles as they have the potential to be able to survive in the Irish climate.

If you wish to contact the HSI regarding any aspect of this article please feel free to do so by emailing science@thehsi.org

PLEASE NOTE:

It is recommended by the Herpetological Society of Ireland that anyone considering acquiring any pet reptile or amphibian does considerable research into their care requirements beforehand. The HSI maintains a policy of best practice with regards to animal husbandry, and that applies to the adult animals as well as the hatchlings initially purchased. With many species of reptile and amphibian the husbandry requirements for the animal may change with age, and this is something that should be considered before acquiring an animal at any lifestage.